A 25 घंटे में 75 पृष्ठों की प्रतिलिपि बना सकता है। A और B मिलकर 27 घंटे में 135 पृष्ठों की प्रतिलिपि बना सकते हैं। B कितने समय में 42 पृष्ठों की प्रतिलिपि बना सकता है?

If P and Q together can complete a piece of work in 15 days and P alone can do it in 45 days, in how many days can Q alone complete that work?

A can lay a railway track between two stations in 16 days and B can do the same job in 12 days. With the help of C, they finished the job in 4 days. In how many days can C alone do the job?